tools/padjffs2/src/padjffs2.c

   1 /*
   2  * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published
   6  * by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <libgen.h>
  13 #include <stdio.h>
  14 #include <stdint.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20
  21 static char *progname;
  22 static unsigned char eof_mark[4] = {0xde, 0xad, 0xc0, 0xde};
  23
  24 #define ERR(fmt, ...) do { \
  25         fflush(0); \
  26         fprintf(stderr, "[%s] *** error: " fmt "\n", \
  27                         progname, ## __VA_ARGS__ ); \
  28 } while (0)
  29
  30 #define ERRS(fmt, ...) do { \
  31         int save = errno; \
  32         fflush(0); \
  33         fprintf(stderr, "[%s] *** error: " fmt ", %s\n", \
  34                         progname, ## __VA_ARGS__, strerror(save)); \
  35 } while (0)
  36
  37 #define BUF_SIZE        (64 * 1024)
  38 #define ALIGN(_x,_y)    (((_x) + ((_y) - 1)) & ~((_y) - 1))
  39
  40 static int pad_image(char *name, uint32_t pad_mask)
  41 {
  42         char *buf;
  43         int fd;
  44         ssize_t in_len;
  45         ssize_t out_len;
  46         int ret = -1;
  47
  48         buf = malloc(BUF_SIZE);
  49         if (!buf) {
  50                 ERR("No memory for buffer");
  51                 goto out;
  52         }
  53
  54         fd = open(name, O_RDWR);
  55         if (fd < 0) {
  56                 ERRS("Unable to open %s", name);
  57                 goto free_buf;
  58         }
  59
  60         in_len = lseek(fd, 0, SEEK_END);
  61         if (in_len < 0)
  62                 goto close;
  63
  64         memset(buf, '\xff', BUF_SIZE);
  65
  66         out_len = in_len;
  67         while (pad_mask) {
  68                 uint32_t mask;
  69                 ssize_t t;
  70                 int i;
  71
  72                 for (i = 10; i < 32; i++) {
  73                         mask = 1UL << i;
  74                         if (pad_mask & mask)
  75                                 break;
  76                 }
  77
  78                 in_len = ALIGN(in_len, mask);
  79
  80                 for (i = 10; i < 32; i++) {
  81                         mask = 1UL << i;
  82                         if ((in_len & (mask - 1)) == 0)
  83                                 pad_mask &= ~mask;
  84                 }
  85
  86                 printf("padding image to %08x\n", (unsigned int) in_len);
  87
  88                 while (out_len < in_len) {
  89                         ssize_t len;
  90
  91                         len = in_len - out_len;
  92                         if (len > BUF_SIZE)
  93                                 len = BUF_SIZE;
  94
  95                         t = write(fd, buf, len);
  96                         if (t != len) {
  97                                 ERRS("Unable to write to %s", name);
  98                                 goto close;
  99                         }
 100
 101                         out_len += len;
 102                 }
 103
 104                 /* write out the JFFS end-of-filesystem marker */
 105                 t = write(fd, eof_mark, 4);
 106                 if (t != 4) {
 107                         ERRS("Unable to write to %s", name);
 108                         goto close;
 109                 }
 110                 out_len += 4;
 111         }
 112
 113         ret = 0;
 114
 115 close:
 116         close(fd);
 117 free_buf:
 118         free(buf);
 119 out:
 120         return ret;
 121 }
 122
 123 int main(int argc, char* argv[])
 124 {
 125         uint32_t pad_mask;
 126         int ret = EXIT_FAILURE;
 127         int err;
 128         int i;
 129
 130         progname = basename(argv[0]);
 131
 132         if (argc < 2) {
 133                 fprintf(stderr,
 134                         "Usage: %s file [pad0] [pad1] [padN]\n",
 135                         progname);
 136                 goto out;
 137         }
 138
 139         pad_mask = 0;
 140         for (i = 2; i < argc; i++)
 141                 pad_mask |= strtoul(argv[i], NULL, 0) * 1024;
 142
 143         if (pad_mask == 0)
 144                 pad_mask = (4 * 1024) | (8 * 1024) | (64 * 1024) |
 145                            (128 * 1024);
 146
 147         err = pad_image(argv[1], pad_mask);
 148         if (err)
 149                 goto out;
 150
 151         ret = EXIT_SUCCESS;
 152
 153 out:
 154         return ret;
 155 }